Coal devolatilizer



Aug. 20, 1946. A. F. Howe:

COAL DEvoLATILI-'ZER Filed June 15, 1944 5 Sheets-Sheet; 2

Aug. 20, 1946. A. F. HowE 2,406,077

COAL DEVOLATILIZER l Filed June 15. 1944 5 Sheets-Sheet 3 WMMW Aug.. 20, 1946.V A. F. HowE 2,405,077

' coAL DEvoLATILIzER Filed June 15., 1944 4 5 Sheets-Sheet 4 Aug. 2o, 1946. A. F. HQwE 2,406,071

y COAL DEVOLATILI ZER l Patented Aug. 20, `1946 UNITED STATES PATENT OFFICE COAL- DEVOLATILIZER Andrew F. Howe, University City, Mo., assignor to Centrifugal & Mechanical Industries, Inc., St. Louis, Mo., a corporation of Missouri.A

Application June 15, 1944, Serial No. 540,512V

` y 7 Claims. 1

This invention relates to devolatilization of coal; and it has Special reference'to a method and apparatus forreducing thesvolatil'e in coal so that slurry coal or small bodies of coal that will pass through a screen having a relatively fine mesh may be readily formed into combustible briquettes and nearly all of the combustible gases burnt during combustion of the briquettes.

An object of the invention is to provide a method and apparatus for removing the volatile from slurry coal and from quantities of small bodies of coal by carrying the same through a heated'oven by a constantly'moving conveyor so that most or a desired amount of the volatile content of the coal will be detached and separated therefrom, withdrawing the separated volatile content from the oven during movement of thev coaly therethrough, andthen forming the substantially devolatilized coal.` into briquettes or:`

other substantially solidbodies convenient for handling, transportatiomand combustion.

Another object of--the invention is to provide an apparatus for `separating a desired amount of the volatile content from slurry/coal `and from quantities of small bodies of coal by the applicationofheat generated by al combustion device using 'and burning the separated volatile content of .the coal, or using and-,burning other fuel or using and burning both saidrseparated volatile `contentand said other fuel, as` desired, andV means for formingv thesubstantially devolatilized.

coal into solid bodies or briquettes that maybe conveniently handled and which will readily burn Without discharging objectionable quantities ofv obnoxious smoke, fumes, and gases.

Another object of the invention is to provide an improved method forreducing the volatile conttent in slurry co-al or small bodies of coal by passing Vor conveyingsaid coal into, through and from a heated oven at a selected 'rate of speed, withdrawing from said oven the volatile content emanating from the coal therein and thereby creating or forming a partial vacuum in said oven, supplying fresh air into Asaid oven to replace r or rreplenish the .volatile content that emanates from the coal therein and which is withdrawn therefrom, and` discharging the coal4 in any form desired after it has passed from said oven.

Other objects will appear from the following description, reference being made to the annexed drawings, in which- 1 Fig. 1 `is a plan View showing one form of an apparatus for practicingv the present invention of substantially 'reducingy the volatile contenty of slurry coal or quantities of small bodiesr of coal formed.

Fig. 2` isa vertical longitudinal sectionalview of an apparatus for reducing the volatile content of slurry coal or of quantities of small bodiesoi coal, and also forming the devolatilized coal into briquettes or solid bodies. Y f

Fig. 3 is an enlarged sectional view of a portion of the conveyor for the slurry coal or srnall particles of coal and of one form of device for shaping the coal into solid bodies or briquettes.

Fig. 4 is a still further enlarged sectional view of a portionyof the device that shapes the coal into solid bodies or briquettes. Y

Fig. 5 is a plan view of a portion of said device.

Fig. 6 is. a perspective view` of a solid body or briquette of dev olatilized slurry coal made by the apparatus of the present invention.

Fig'. 7 is avertical cross-sectional view on the `line '1 1 ofFig. 1.

y Fig( 8 is aside elevationof the apparatus shown` Fig. 12 is a perspective view of another form or shape of a solid body or briquette of devolatili'zed coal formed bythe rolls shown in Figs. 10`

and 11.

Fig. 13 is a vertical'longitudinal sectional view of an apparatus for practicing the invention by the use of fuel gas only.

The apparatus shown for removing volatile from slurry coalor from quantities of small bodies 1 of coal comprises Ya furnace having refractory enclosing walls I. This apparatus is an embodi` ment of an idea of means comprising part of the` invention for successfullyV practicing the methodv portion ofthe invention. If desired, the Vfurnace may 'be divided-into at least two combustion chamber'sor fire-boxes 2 by a partition 3, also preferably composed of refractory Vmaterial. Each combustion chamber ofthe furnace may -enclose a chain grate yStoker `Il of known construction and actionfmounte'd at one side ofV they rotative supporting roll 6. The rolls 5'and6 are preferably. ofY the samev diameter and rotate about horizontal axes in the same horizontal plane. Y

t the furnace.

3 Y c In the modification of the apparatus shown, there l Vare two combustion chambers 2 each having therein a chain grate stoker 4 and having the driving rolls for r`said respective chain grate stokers mounted at opposite sides of the furnace.

. 3| operated by an electric motor 32 through suit- .Y

ends of the furnace. The shaft 20 may be constantly or intermittently rotated by connections able speed reducing gearing (not shown). Between the sprocket Wheels 23 and I9 the chains I8 operate along and are supported by rigid rails Within the furnace, the ends of the chaingrate As shown, an

` stokers 4'o'perate'pn,and'along'supportingrails1. Each driving 'roll 5 mayb'e rotated' intermittently'j or continuously as desired by operating mecha-v nism provided for that purpose;

electric motor 8 is operatively connected withthe l Y t shaft 9 of each operating roll 5 yby suitable speed Any knowntypev of coni-2 reducing gearing I 0.

nection from the motor 8 to the shaft A3' ofeach t driving roll 5 may be employed. Solid fuel such f as kcoal may be fed onto the endofyeach grate 4 f above Yor adjacentto the driving roll 5 through a hopper-Y II. The hoppers II extend Vthe' full width ofthe respective chain grate stokers 4, and 1 will discharger lthe coal onto said grate stokersl for movementinto the furnace. The two grates, shown move inlopposite directions across the furnace .through the respective chambers 2, fromv which the burnt gases, smoke, andlikeproducts ofcombustion are conductedrand passthrough flues iI2; One of the ues I2 ,opens fromV eachV Vcombustion chamber 2 at the opposite side of the`l Each com` bustionA chamber4 2 is provided Witha cover YI3, :sa

preferably of. metal and which may beof archil formationand whichprevents ignition and com-` bustion of a'slurry. coal or Quantities of small furnace .from the stoker hoppers Il.

bodies fo coal conveyedA through the oven I 4 above The ovenV I4 is wholly by ag top wall I5 which may be composed* ofthe Ysamerefractory material iormingthe'walls I. and;V 3, or of other appropriate material as desired..V An1 elongated-horizontal inlet fopening'zIS is formed out of communication' with 'the combustion chambers 2 and is covered coal are deliveredonto the upper stretch ofthe y 33 which support the upperstretch ofK the conveyor inra straight horizontal' plane; andfprevent 1 sagging thereof. iIf desired,the"intermediate portion of the conveyor bottom walls 29 between the chains I8 may be supported by any appropriate device. It will be noted in Fig. 2 that the bottom walls 23 of the conveyor pans 29-30 are close to -the covers I3 which form the bottom wall of the *oven I4 through which the coal is carried by the conveyor and subjected to heat emanating from Y the furnace.VV

The slurry coal or quantities of small bodies of conveyor comprising the pans 29-30. The coal is delivered in controlled quantities Vthrough a chute 34 `having a discharge opening 35 at'its lowerend extending nearly the fullwidth of thev conveyor between the side walls 30 of the piv- ,otally connected conveyor pans. The walls of the chute 34 forming the discharge opening 35 ter-Y minate immediately above the'side walls 30 of thef conveyor pans and doV not interfere WithY the free g movement and operation of said conveyor. A hopper 35 for containing the slurry coal Yor quantities of rsmall Vbodies of coal tov be processedv by this invention opensvinto the upper end of the chute 34. Measured quantities of slurry coal or fof the small bodies of coal contained in the hopper V35 are moved from said hopper and discharged Vinto the chute34 automatically and as an inci- A rotary l shaft 33 extends horizontally across the comf-V Ymunication from the hopper 35 to the chuteA 34 'concentrically with opposite portions 3'I andl38 dent to operation of the apparatus.

Tof theV Walls connecting'said hopperv withI said through one of the walls I of thev furnaceV aboveY the cover I3, anda complementary horizontaliouta Y let opening I'I is formed through the opposite Wall lof the furnace. vThe, conveyor forv theslurry" coal `or quantities of smallbodie's of coal passes;V

through the opening I6 into the oven I4 and' passes .from saidV oven through the opposite complementary openingul'l. The conveyor itself is;

`- of ,novel` construction, comprising Vat least two endless series of pivotally connected y links YI8 forming endlessV chains engaged with two axially alined sprocketwheels VISattached to a rotary 1 actuator shaft beyond,V the outlet openingV I'I.1 The sprocket chains I8 engage similar sprocket wheels 2I, 22 and 23 attached to shafts 24,25 and 26, respectively. All of the shafts 20, 24, andv 26 extend horizontally and parallel with Yeach other. 'It is evident that, when the shaft 20 is rotated in a counter-clockwise direction, as indi-v cated by the arrow 21V (Fig. 2) the sprocket wheels I3 Will be rotated in the same direction and' will;

in theqi're'ctioii of the arrow 2a. Y' 1 Y Y The` complementary links I8/ on chainssupport -pans veach comprisingY a bottom thereby move both or all of the sprocket chainsV I8 Wall 29 extending therfull distance betweenthev the respective tworrsidechains I8, and two end walls 30. `The Y Vheight'of the side walls 33 ,of thepans is less than. theriverticalrwidth of the vopenings VIGand IIfintoV and from the oven I4, sothat the conveyor'comprising theV sprocket chains I8 and the pans l-23-930 jmay pass'freelythrough said openings.

The pair of shafts rand 24 and the complemen,

tary pair of shafts 25 and yZtare beyond opposite chute.

connectedcby4V walls A4I] extending rradially from the Ashaftf36, and cooperating withthe Wa11s39 to form' measuring compartments 4 I'. Each measuring 'compartment 4I will Yreceive and move a quantity of slurry coal orrsmall bodies of coal from the hopper during rotation of the measuring device and successively discharge said quantities into the chute 34 from which the coal moves by gravity Aonto the conveyor. The shaft v36 is rotated by a'connection 36' operated by the rotary conveyor shaftiZB only whenAV the conveyor isY operated bythe shaftA 2IJ (Fig. V8).

A pipe 42 opens through the topV wall I5 of the oven I4 and constitutes an outlet passage for Withdrawing gases and volatile liberated from the coal in and passing through the oven I4. r.A'vacuum pump 43 operated by connections 44 driven by al motor 45 is connected to the eluent end "of theV passage 42 and functions to withdraw gases and" volatile from the oven and form or create a partial vacuum therein. The oven' I4 is airtight, and receives no outside air except .through -the openings I6 and I1. This feature substantially aids the emanation and withdrawal of volatile content from the coal Within Vthe oven. From the Y f vacuum pump 43, a pipe-46conducts ythe gases and volatile into a tank 4'I which may be locatedin any place desired and which is shown between".y

one of the walls I ofthe furnace'and the adja-' cent pair of shafts 2and 241-7A pipe 348 opens fromtheginsideoffthe lupp'erfend of the tanliz'pllr'l'V Thefshaft 3B is rotated byvdrivingfcon-k nections from the motorl. A pair of circular end Walls 33 are attached -to` the shaft 36 and are Y sacem? and has .stretches or .extensions 49.:across-1each combustion .chamber :'2 substantially .above ithe stokergrates 4.and below the.covers |53 ioftherespective combustion chambers 2. The stretcheso extensions V4.9 are providedwith numerous gas outlet` openings '50 :for.discharginggasfinto the combustionchambers for mixture with the gases and fumes rising from the v.burning coal V`en thek stoker grates, and thus burning said gases constantly during voperation of the apparatus. 'By making the-areas of the holes 50 of proper size,:they will co'ntrolthe pressure of the gases .pumped therethroughanddispense .with .the necessity of .using valvesior the like in connection with .the pipe .138 ofithe. :extensions '48.

L'Ilwo Aparallel `horizontal shafts A5IA and 52;a're supported forrotation above the conveyorZB-B adjacent .to .and beyond the outlet .opening :l1 from the oven -M :and between the v'furnacewall I and the vertical plane or discharge end oflthe shaft 2i).V A 'pair oflsprocket'wheelsf53.is attached to'eachof said shafts 5I .and:52. An endless device fror forming the .'devolatilized coal intosold bodies or briquettes is enga ged upon the sprocket wheels 53. .Saiddevice comprises as'eries of pivotally connected .transversely elongated 'links 54 in which are formed `molds .'orcutters 55;forcut ting and compressingthc layer of substantially devolatilized sheet of slurryY coal orsheet of small bodies of coal spreadupon'the conveyor bottom walls '29'.and which had. been carried Athereby through the heated oven I4. The moldsxor cutters55 cut vand compress the substantially `devolatilized layer of coal into solidV bodies orbriquettes 56 (Fig.r 6), leavingzsaid solidbodies .or .briquettes 56 on'the .conveyor for :discharge therefrom Ibeyond the s'haft2. vOne of the shafts `5| Aorf52 may berotated by the connections 3l .operated 'by the motor 32 for rotating the shaft 12a (Fig. '8),or otherwise as desired. Thus, lthe conveyor and the 'briquetting device may be concurrently operated.

.From the conveyor 252-30, the briquettes are discharged intoa chute T51 and conducted to a rotary discharge fdevice comprising a shaft 58 attached Vto circular end Walls-"59 connectedby Walls 6i) extending radially from 'the shaft 58. The shaft 53 is rotated byconnections 58 operated by :the motor 32. The walls 5S-6U form compartments 6| lwhich receive quantities of briquettes fromthe chute :51.and deliver them into a discharge chute 62. 'Any particles of vcoal adhering to the conveyor may bedetached there-V from bya brush-63 (Fig. 2) supported andoperated by a rotary shaft `lit below the plane of the shaft 2G. 'I'he brush 63 maybe rotated in'th'e direction o'f the arrow f55 (Fig. 2) and thereby impel and cause the detached particles of coal to drop by'gravity into Va space 66 from vwhich they may be Vremoved and replaced, or otherwise disposed of as desired.

The -end of each combustion chamber 2 .opposite from the fuel feed h'opper Il and'driving roll 5 discharges the ashes andwaste remnants of the burnt coal into a'closed ashpit'61. -Above each ashpit 61, the ends of -thecornbustion Vcharnbers2 are-provided with clean-out doors'which are closed during operation of the apparatus and which lmay be opened to Vpermit the respective combustion chambers to be `cleaned Vby removal of solids therefrom. Beyond the'ends vof thev furnace, Yenclosing Walls 69 extend. At one end the fchute -34 opens through the topof theenclosing wall A69 'which encloses the lmechanismfcomprising the shafts 25, S26, adjusting devices 10 6 for the fshaft 25, '.etc. .At i the opposite :endthe mechanism .i comprising 'the shafts' 120, 24, lthe briquetting device, .the 'mechanism' "58-159-'161 and ithebrushi63-B.4, are enclosed ina-com par-tmentformed by Said enclosing wall .69.

YAir .maybe admitted into the space 'enclosed by the Walls 'I9 and th'ence intothe oven-'Min order .to prevent formation of excessive'va'cuum therein 'by operation of the vacuum pump .43 which withdraws gases and air from theoven Ifll through 'the pipe 42. An air inlet device 1| opens into one end of said space .which is Venclosed by the kwalls 69 Yand Vfunctions'to admit air into said space and thence into .the oven f|4th'rough.`the openings I6 andtlr'l. Thus, theair inthe oven isreplenished andv formation of vexcessive :vacuum therein isprevented.

By. themodication showninFigs. .9, 10=andf I1, thedevolatili'zed coalon the conveyor i2 9-430 may becompressed and cutintosolidbodies orlbriquettes 12 (Fig. 12) otherwise than .by the `deviceshown in Figs. A3, 4 and .5. In substitution for said zdevice, the said mechanism shown in.

Figs. `9, v10V and 11 may `be used for compressing, shaping and cutting the coa'l on the conveyor 9435 into solid bodies or briquettes. Anendlesspresserdevicei13 is mounted on thesprockety v a roller 'M extends parallel with the upper sur-V face of the conveyor 29-30 and `has numerous circumferential and longitudinally spaced cutting knives or anges 15 which cut the compacted devolatilized coalinto parallel longitudinal-strips y during movement ofthe conveyor 21S-30 under the .said roller 1.4. Adjacent to v:the rol1erf14 another roller `16' havingnumerous longitudinal cuttingknive's or flanges 11 .is arrangedjtorcut transversely 'the pressed devolatilized .rcoal `that had been cut into parallellongitudinal:stripsfby the circumferential flanges'or cutters 15. The roller 14 with its circumferential flanges .or cutters 15 and the roller 16 Withgits longitudinal flanges or cutters 11 cut the pressed Vdevolatilizl-:id coal intosaid solid bodies or briquettes12 which are discharged or dropped Ifrom the conveyor 29-30 into th'e hopper 51, asdo the -solid bodies or briquettes 56. The relative positions ofthe rollers 14 -and 16 may be reversed, and they may be positively driven or freely rotative if desired.

The modication shown in Fig. 13 is designed for the exclusive use of gas asv afuel Within the combustion chambers. That is, from the said modication of the invention shown in Fig. 13, the coal Stoker gratos 4, motors 8 and connections therefrom for operating said stoker grates, the ashpits 61.for receiving ashes andsolidrefuse from the combustion chambers 2, and other parts required when coal is used as a fuel and ,that are not required when gas alone is used as a fuel, are omitted. In this form of the invention, .the

vertical height of the combustion chambers 18 manufactured gas may be supplied into the tank lll.:v or .directlyto -the pipeV I8V or stretches 49,. through -a pipe 80, so that a'constant supply of i Y a suiiicient amount of gas is always delivered and supplied to the burners 'i9 when theapparatus i -is' `in use.. Necessaryair may be admitted intoV the. combustion chambers'l rthrough openings IBIV provided for that purpose. In other particulars, the construction and form of the apparatus i shown Vin Fig. l3is th'e sameV as thatalready described and as shown in Fig. 2, and like reference q numerals are applied to the same parts.k .Y

"From the `foregoing disclosure, it is evident K that this invention produces solid bodies or briquettes of devolatilizedcoal ready for satisfactory Y userV as `substantially smokeless fuel. 'The approximate'temperatures to which theV coal must j besubjected while the coal is .Withinjthe oven VIll or during movement of the coal through said oven may be predetermined and the apparatus mayv be regulated to supply said required temperatures. The speed of continuous or intermittent movement of the coal through the oven I4 maybe regulated as desired by controlling the speed Vof continuous or intermittent operation of -the motor 32 and the connections therefrom` for rotating the shaft 20 and moving the conveyor continuously or intermittently. The apparatus specifically disclosed isY for Aprocessing slurry coal to lower the volatile thereof to any movement of said coal through 'said oven,V and compressing said coal flatwise on said conveyor only after said coal has been moved out of said oven. v e

4. An apparatus for reducing the volatile content of a loose and unpressed layer of slurry coal and small bodies 'of coal," comprising .walls forming and enclosing an oven and including two opposite walls having elongated horizontal openf ings Ytherethrough near the bottom of said oven, said walls also forming and enclosing a;com. lbusti'on chamber below said oven forY heating the same, an impervious metallic coverforsaidicom-f bustion chamber forming the bottom Wall of said oven and supported Vby and cooperating ,With said first walls toseal said oven from said combustion chamber and also Qto heat said oven, afseriesfof four parallel shafts outside of said oven and said combustion chamber, an endless conveyor .sup-

ported by said shafts and extending: through said l oven and through said openings adjacent toy said extent desired, and such volatile may be used and consumed as fuel in the combustion chambers that supply heat for devolatilizing or lower-.

ing the volatile content of the coal.

The invention may be varied in equivalent particulars other than those specically shown and described Ywithout departure principle thereof.

v 1. The method of reducing the volatile confrom the nature and cover for receiving and moving through said oven said loose and unpressed layer of saidcoal, other walls forming 'two compartments enclosing said shafts wholly out of Vcommunication with said oven, a measuring device operated by one of said shafts for delivering a layer 'orV measured quantities of saidfcoal onto said conveyor inone of said I compartmentsl adjacent to said one shaft, a 'tank enclosed in the other oneof said compartments, means forming a passage. for conducting from said oven into said tank volatile content emanattent of slurry coal, which consists in depositing a y layerpof slurryY coal upon a vmoving conveyor,

` moving said conveyor and the layer of loose and unpressedslurry coal thereon into and through l" Va. heated oven 'containing onlyair and the lvola-1 tile and gases emanatingr from said coal, Withdrawing said air and saidfvolatile and gases em- Y anating from said coal duringmovement of lsaid coal through said oven, and compressing and applying pressure to form said layer'of coal into solid bodies or briquettes after said layer hasv been moved through said oven by said conveyor.

.2.' The method of reducing the volatile content of slurry coal or of quantities of small bodies of coal, which consists in depositing a loose and unpressed layer of said coal upon a moving conveyor, moving said conveyor and 'said loose and unpressed layer of said coal thereon into and through a heated oven containing only air and` the volatile and gases emanating Vfrom `said coal,` and creating andforming a partial vacuum in and withdrawing said air and said .volatile and gases emanating from saidcoal in said oven during movement of lsaid coal through said oven.

V3. The method of reducing the volatile content of Yslurry coal or of quantities of small bodies of coal, Which consists in depositing a loose andun-l pressed' layer of said coal upon a moving conveyor, moving said conveyor and said loose and unpressed layer of said coal thereon into Yandv through a heatedrovencontaining only yair and the volatile and gases emanating from said coal,

.ing fromfsaidcoal in said oven, and a burnerin said combustion chamber having connections f communicating. withfsaid tank for burning said Y volatile content and heating said oven., l

5. An apparatus for reducing the volatile content of a loose andqunpressed layer of slurry coal and small bodies of coal, comprising Iwalls form-v ing and enclosing an oven and including two opposite walls having elongated horizontal openings therethrough near the bottom of said oven,said walls-alsogiorming and enclosing a combustion chamberbelow ksaid oven forrheating the same,` an4 impervious metallic cover for said combustion chamber forming the'bottom Wall vof said-'oven and supportedby and cooperating with said rst walls to Iseal said oven fromsaid combustion' chamber'v and also to heat said oven, ran endless conveyor extending vthrough said oven and through said openings adjacent to said cover for receiving and moving through said Voven said Yloose and unpressed layer" of said coaLYmecha-V nism for moving said conveyor and thereby said layer of loose and unpressed'coal through said oven and discharging said coal therefrom, other Walls forming two compartments enclosing por-Y tions of said conveyor beyond said oven, a measuring device operated by said mechanism for delivering a (layer, of measured quantities of said coal onto said conveyor in one ofi-said compartments, a tank enclosed in the other lone ofsaid compartments,` a. burner in Vsaid combustion chamber; andY meansv for conducting: from said g tank to said burner Yvolatile content emanating from said coal in said oven.

creating and forming; a partial vacuum in .andY

withdrawing saidV air and said volatile and gases 1A emanatingv from vsaid coal in@ said ovenduring 6. An apparatus for reducing the volatile content of a looseV and unpressed layer of. slurrycoal and small bodies of coal,Y comprising walls form-j ing and enclosing anoven and includingV two opposite Walls having elongated horizontal open'- ings therethrough near the bottom of said oven,` said Ywalls also forming* and enclosing a combus` tion chamber below said oven for heating the same, an impervious metallic cover for said com-4 bustion chamber forming the bottom Wall of said oven and supported by and cooperating with said rst Walls to seal said oven' from said combustion chamber and also to heat said oven, an endless conveyor extending through said oven and through said openings adjacent to said cover for receiving and moving through said oven said loose and unpressed layer of said coal, mechanism for moving 'said conveyor and thereby said layer of loose and unpressed coal through said oven and discharging said coal therefrom, other walls forming two compartments enclosing portions of said conveyor beyond said oven, a measuring device operated by said mechanism for delivering a layer of measured quantities of said coal onto said conveyor in one of said compartments, a burner in said combustion chamber, and means forming a passage for conducting from said oven to said burner the volatile combustible content emanating from said coal in said oven.

7. An apparatus for reducing the volatile content of a loose and unpressed layer of slurry coal and small bodies of coal, comprising Walls forming and enclosing an oven and including two opposite walls having elongated horizontal openoven and supported by and cooperating with 'said g first Walls to seal said oven from said combustion chamber and also to heat said oven, an endless conveyor extending through said oven and through said openings adjacent to said cover for receiving and moving through said oven said loose and unpressedlayer of said coal, mechanism for moving said conveyor and thereby said layer of loose and unpressed coal through said oven and discharging said coal therefrom, other walls forming two compartments enclosing portions of said conveyor beyond said oven, a meassuring device operated by said mechanism for delivering a layer of measured quantities of said coal onto said conveyor in one of said compartments, and mechanism in the other one of said compartseparate combustible briquettes.

ANDREW F. HoWE. 

